MRC1 and Leigh syndrome: According to the study by Møller et al., the cumulative incidence of EC in LS patients carrying MSH2 germline mutations was as high as 51% at the age of 70, ranking first among the four MMR genes of MLH1, MSH2, MSH6, and PMS2, and significantly higher than MLH1 (34%) and PMS2 (24%) [46].